Method of correcting the pitch in drive chains



F. L. MORSE.

METHOD OF CORRECTING THE PlTC-H IN DRIVE CHAINS.

APPLICATION FILED NOV. 10, I919.

Patented Jan. 31, 1922.

UNITED, .STTAT ES 'oF'IrrrAoA, NEW Yomg A CORBORATIQN on NEW Y RK,

METHOD or CORRECTING THE PITCH 11v DRIVE- CHAINS. i I

' in Drive Chains, of which improvement the following is a specification.

This invention relates to .a method of correcting the pitch of drive chains and particularly that form of chain composed of links formed of aplurality of plates connected together by multi-part pintles, such as two-part pintles, in which both parts extend through openings in the ends' of the ad jacent link plates and bear upon each other throughout the width of the chain.

In this well known standard form of chain it is important that the pitoh.should be main tained as accurately as possible, andforthis purpose a standard schedule of dimensions as to the'relative sizes-and thicknesses of link plates and pintle parts is kept and followed in the manufacture and assembling of the chains. There is, however, some variation in the link plates, due to inaccuracy in punching and variation in the character or hardness of the metal stock from which the plates are punched, and this may result in slight variations in pitch as the chains are subjected to initial wear. and the joint pins become seated in the openings-of the respective links.

The object of my invention is. to compensate for these variations and restore the chain to the correctvpitch after such initial wear has taken place. This is accomplished "by subjecting the assembled chain to such initial wear by running the same under ten sion for a period of time, then accurately measuring the pitch of the links to determine what the variation is, and then substituting for one of the pintle parts another of different thickness sufiicient to restore the correct pitch of the chain. v

In the accompanying drawing, Figure 1, is a longitudinal section showing several links of a standard form of chain; Fig. 2, a transverse section of one of the pintle parts,'the seat pin, upon a larger scale, different thicknesses being indicated in dotted lines; and Fig. 3, a similar view of the other pintle part termed the rocker.

While my improvement may be employed in connection with various forms of drive size and shape and restore the correct pitch.

. "Application filed November 10, 1 9 19..: a?

chains having multi-part pintles, I have illus- I PA IE QFFICEP? FRANK 1:.. ivronsn-or IrnAoA, NEW YORK, nssrenon'i'ofriin'lvron'sn 01-min coMrANY,

Specificationof Letters Patent. PatentdJ 3 11." 31, I

trated the same in connection with awell known standard form of chain having links composed of a plurality of plates 5, which are formed by being punched out of sheet metal stock of the desired thickness in the usual way, and have openings of suitable the pintle parts. As shown, the pintle is composed of two parts, aseat pin 6, .and a rocker pin 7 both extending through the openings in the ends of the plates of adjoininglinks, and bearing f upon each other the chain. The seat pin at each j oint is held by the" plates of -one .link while the rocker pin engages theplates of the adjoining link as the parts turn, one upon the other within the openings in the link plates.

The chains are first assembled with the standard size pintle parts for producing a theoretical correct pitch, but after being subpunched in their endsfory throughout. substantially the full width of V I jected to initial wear, it will beseen, that on account of the varlations and inaccuracies above referred to, the pitch may be slightly changed. This inaccuracy may then be cor.- rected by changing the thickness of one of the parts of the pintle, for instance, if, after 7 initial wear, it should be found by accurate measurement that thepitch has lengthened, then a slightly thicker pintle part would be inserted or substituted for the one used, whichwould compensate for-the variation In practice the sizes of the pintle parts, as to the different thicknesses, vary from each otherlby one thousandth of an inch, so that even very slight inaccuracies may be corrected; This change may be made by substitutinganother seat pin or. another rocker pin, or both, as preferred, but the correction is usually made by changingthe rocker pin, as in the standard chain this pin is not fastened to washers at its ends, as is the seat 7 am. 1 It will now be apparent that by means of my improvement the variations in the metal stock of the link plates, and the inaccuracies of punching may be compensated for, and the drive chains restored to correct pitch.

Having now described my invention,what I claim as new and desire to secure by Letters Patent is: r 1

1. The method ofcorrecting the pitch in drive chains having multi-part pintles, which consists in assembling the links upon stand ard size pintles, then running the -chain under tension for a period of time, then accurately measuring the pitch, and substituting for one of the pintlerparts another of v diflerent thickness'sufiicient to restore the 7 correct pitch of the chain.

2. The'm'eth'od of correcting the pitch of drive chains having two part pint1es,-com- Y my hand.

FRANK L. MORSE. 

